Abnormal phenomena and failures often occur in valve-type arresters during operation. The relevant personnel on duty should analyze and judge the abnormal phenomena and take timely measures to deal with the failure.

Phenomenon 1

Cracks were found in the arrester porcelain sleeve during thunderstorms.

Measures: Do not make the arrester out of operation as much as possible, and deal with it after the thunderstorm.

Phenomenon 2

Flashover caused by cracks in the arrester porcelain sleeve, but not caused by system grounding.

Action: If possible, the arrester of the faulty phase should be deactivated.

Phenomenon 3

The valve-type arrester explodes during operation, but it has not yet caused the system to be permanently grounded.

Measures: After the thunderstorm, open the isolation switch of the faulty phase to deactivate the arrester, and replace the qualified arrester in time.

Phenomenon 4

The system has been permanently grounded after the explosion

Action: It is forbidden to use the isolating switch to operate the deactivated arrester.

Phenomenon 5

The valve-type arrester action indicator burns black or burns inside, and there are burn marks or burns on the connection point of the grounding lead.

Reason: There may be internal defects such as valve resistance failure, deterioration of spark gap arc extinguishing characteristics, etc., resulting in increased power frequency freewheeling, etc.

Measures: Do an electrical test or dismantling inspection of the arrester in time.

The above are common abnormal phenomena and troubleshooting of valve arresters, I hope they will be of great help when you face similar problems.